Assess Different Rate and Source of Nitrogen Fertilizer on Wheat (Triticum aestivum L.) Crop Production under Drought Stress Condition

BACKGROUND: Climate change is expected to accelerate, leading to further drought stress in large areas of the world. Considering wheat's status as a dietary staple for a significant portion of the global populace, it becomes apparent that attaining a thorough comprehension of the fertilizers effectiveness, widely utilized in current agricultural practices, holds paramount significance for the enhancement of global food security. OBJECTIVES: This study was done to evaluate the effect of different rate and source of Nitrogen fertilizer on quantitative and qualitative parameters of Wheat affected drought stress condition in two moderate climate regions. METHODS: Current research conducted according factorial split plot experiment based on complete randomized block design with three replications. The experimental treatments included three levels of drought stress [control or no stress, irrigation until the booting stage (booting-stage drought or BSD), and irrigation to the soft dough stage (Maturation-stage drought or MSD)] in the main plots. Different source of Nitrogen fertilizer [including Urea (U) and Ammonium Nitrate (AN)] belonged to first subplot and three level of different rate of Nitrogen [Normal (N) amount according soil test, 50% higher than normal amount (N+50), and 50% lower than normal amount (N-50)] belonged to second subplot. RESULT: In addition to drought stress leading to a decrease in 1000-grain weight, the application of nitrogen fertilizer at a rate of 50 percent above normal caused an increase in 1000-grain weight of wheat compared to normal treatments and 50 percent below normal. Grain yield in the control treatment without drought stress was higher (5792 kg.ha-1) than the two drought stress treatments, and grain yield with ammonium nitrate fertilizer application (4853 kg.ha-1) was higher than that with urea fertilizer application (4275 kg.ha-1). The highest biological yield was for ammonium nitrate fertilizer and in the control treatment without drought stress, at 14908 kg.ha-1. The highest grain protein percentage of 12.81% was obtained in the irrigation treatment up to the inflorescence emergence stage and with the application of ammonium nitrate, and increasing the amount of Nitrogen fertilizer application led to a further increase in grain protein percentage. CONCLUSION: Use of Baharan Wheat variety in studied region at non drought stress conditions and application of Ammonium Nitrate fertilizer at a rate 50% higher than the recommended level by soil test can be advised to producers.